Automatic rewinding apparatus



Aug. 16, 1966 w. Y. BENSON AUTOMATIC REWINDING APPARATUS Filed May 27,1964 R O T N F- V N WILFRED Y. BENSON ATTORNEYS United States Patent3,266,745 AUTOMATIC REWINDING APPARATUS Wilfred Y. Benson, Natick, Mass,assignor to Anelex Corporation, Boston, Mass., a corporation of New YorkFiled May 27, 1964, Ser. No. 370,593 5 Claims. (Cl. 24267.4)

This invention relates to automatic rewinding apparatus, moreparticularly of a type which reels a web between one roll and another,reversing the direction of winding as the supply becomes depleted fromeither roll. Mechanism of this kind is particularly useful in handlinginked printing ribbons in printing machines, typewriters, and the like,although it finds many applications in reeling other types of web andsheet materials.

It is the primary object of the present invention to provide an improvedautomatic rewinding apparatus, which senses the alternate depletion of aweb from either of two rolls and quickly reverses the winding direction,by means of an improved mechanism of simplified and reliableconstruction. It is a feature of the invention that a single controlmechanism is utilized to sense the depletion of Web from either roll.Further objects and advantages of the invention will become apparent asthe following description proceeds.

The invention may be carried out in a winding apparatus which includestwo rolls arranged on parallel axes for winding an elongated web, suchas a printing ribbon, from one to the other and back again. A portion ofthe ribbon extending between the rolls is arranged for engagement of onesurface with paper which is to be printed, and of the opposite surfaceby a typecarrying member which produces an inked impression on thepaper. Such a reeling arrangement is conventionally used in typewritersand other printing machines, and the rolls may be driven continuously orintermittently.

Each roll is drivingly connected with the output element of one of apair of clutches, so that either roll can be driven by engaging itsconnected clutch. Each clutch has an input drive element which isconstantly driven by motive means such as an electric motor, the twoinput elements being driven in opposite rotary directions; uponengagement of either clutch, the connected roll is driven in a directionto wind the ribbon thereon and withdraw the ribbon from the other roll.Reversible pressure-actuated control means are provided foralternatively engaging either clutch, so that the direction of windingcan be reversed. In a preferred form, electromagnetic clutches arealternatively energized by momentary contact of an actuating elementwith pressureactuated switch means.

An improved control mechanism is provided for sensing the depletion ofthe ribbon from either roll and actuating the control means in response.This mechanism includes a single paddle mounted on a rock shaft foroscillatory movement into momentary peripheral engagement with first oneand then the other ribbon roll. The rock shaft also bears the actuatingelement, for oscillation with the paddle through an are determined bythe interferences of the paddle with the two ribbon rolls. Completion ofthe unwinding of either roll results in movements of the paddle and theactuating element to one terminal position, in which the elementoperates the switch means and thus. reverses the direction of ribbonfeed.

The oscillating motion of the paddle is produced by a pair of cams,driven by the input elements of the clutches in opposite angulardirections; these cams alternately release each of a pair ofpivotally-mo-unted levers for movement by biasing means to oscillate acrank "Ice connected to the rock shaft. This oscillation is notpositive, being induced only by a spring bias, and so is limited by theinterference of the paddle with the ribbon rolls, until the terminalposition with respect to either roll is attained. Alternating detectionof the diameters of the two ribbon rolls is thus obtained by means of asingle sensing means, which automatically reverses the ribbon feeddirection as either roll becomes depleted.

While the specification concludes with claims particularly pointing outthe subject matter which I regard as my invention, it is believed that aclearer understanding may be gained from the following detaileddescription of a preferred embodiment thereof, referring to theaccompanying drawing, in which FIGURE 1 is a schematic diagram of therewinding apparatus and FIGURE 2 is a perspective diagram of a portionof the apparatus shown in FIGURE 1.

Referring to FIGURE 1, the illustrated rewinding apparatus includes apair of ribbon rolls 2 and 4, which are mounted on drive shafts 6 and 8,respectively, for reeling a ribbon 10 from one roll to the other. Theribbon is guided by rolls 12 for impression of an image by conventionaltype mechanism (not shown) in any conventional printing process whichutilizes such an inked ribbon. In the condition shown in the drawing,the ribbon is fully wound on a roll 4 and depleted from the roll 2, andit is the function of the apparatus to reverse the direction of ribbonfeed from that indicated by the arrows, and to rewind the roll 2,repeating the process cyclically so as to continually present a freshribbon area for printing. It should be understood that the device isparticularly useful for printing ribbons of the type in which the inkredistributes itself after each impression, so that it may be re-r-eeleda number of times and continue to yield a satisfactory impression.

The rolls 2 and 4 are connected by the drive shafts to output elements14 and 16, respectively, of a pair of electromagnetic clutches. Theinput elements 18 and 20 of the clutches are driven continuously inopposite angular directions by means of a drive shaft 22, having worms24 and 26 meshed with worm gears 28 and 30, respectively. The worm gearsare drivingly engaged with the input elements by means of hollow shafts32 and 34, which are co-axial with the drive shafts and freely rotatablethereon. Means for driving the clutches include a motor 36 and reductiongearing 38. Alternative engagement of either clutch is secured byenergizing one of the clutch coils 40 and 42 to drive the correspondingroll 2 or 4. In the condition shown in the drawing, the ribbon is fullywound on the roll 4, whose clutch element 16 is currently driving; theapparatus is prepared to reverse the direction of ribbon feed.

According to the invention, alternate detection of the diameters of bothribbon rolls is performed by a' single paddle 44, which is caused tooscillate between limiting positions determined by its interferenceswith the peripheries of the respective rolls and any ribbon reeled onthem. A maximum or terminal arcuate displacement of the paddle, whichindicates depletion of the ribbon from either roll, is translated into areversal of the feed direction. The paddle is shown in such a terminalposition, bearing against the surface of the roll 2. The complete rangeof variation of the interfering positions during a reeling cycle isshown in dotted lines with respect to the roll 4 and to the ribbon nowreeled upon' it.

Referring to FIGURES 1 and '2, the paddle 44 is carried by a rock shaft46, which also bears a crank arm 48 and a clutch-actuating element 50.-An oscillating movement is induced in the rock shaft by means of a pairof levers 51 and 52, and cams 54 and 56 secured to the hollow shafts 32and'34, respectively. Each cam has a flat 58, one being angularly out ofphase with the other, so that the levers are alternately released froman inactive position in which the lever 52 is shown, and allowed to movetoward a terminal position in which the lever 51 is shown. The leversare mounted pivotally engaging a crank pin 66, as the lever is releasedby coincidence with the fiat 58. A tension spring 70 is connectedbetween the axle 62 and the crank pin 66, to bias the crank toward aneutral position and thus cause it to follow the arm 68 of either leverwhich is currently active.

In operation, as either lever is released by coincidence with the fiat58 of its cam, it is biased by the spring 64 to rock the shaft in acorresponding direction. However, this angular motion is limited by theinterference of the paddle with the corresponding ribbon roll, and thelever does not actually contact the flat of its cam until the ribbon isfully depleted from the corresponding roll, as is the case with roll 2in the illustrated terminal posiiton of the paddle. At this juncture,the displacement of the actuating element 50 is just sutficient toactuate a corresponding one of two appropriatelyplaced microswitches 74or 76, through adjustable. studs 78 borne by the actuating element.These switches control suitable circuitry for reversing the ribbon feeddirection by disengaging the element 16 of one clutch and engaging theelement 14 of the other, thereby to re-reel the ribbon from the roll 4to the roll 2.

It will be understood that upon the subsequent oscillation of the paddletoward the roll 4, the angular displacement of the paddle and of theactuating element will be limited by interference With the reeledribbon, so that the switch 74 will not be actuated until such time asthe roll 4 becomes depleted; at that stage, the switch 74 will beactuated to reverse the drive once again.

While various forms of circuitry may be employed for reversing theclutch engagements under the control of the switches 74 and 76, a relaydevice 82 is shown by way of illustration. The relay includes a doublethrow contact 84, which energizes the clutch coil 42 while the relaycoil 86 remains deenergized, and energizes the clutch coil 40 uponactuation of the relay. In the state shown in the drawing, the switch76, which is of a normally open variety, is being actuated by theelement 50. The relay will then become energized to raise the contact84, thus reversing the energization of the clutch coils. A holdingcontact 88 is provided to maintain the energization of the relay coilafter the release of the switch 76, and the holding circuit is completedthrough the normally-closed switch 74. At such time as the ribbonbecomes depleted from the roll 4 and the actuating element 50consequently strikes the switch 74, the holding circuit will be brokenand the relay will release to reverse the clutch energization onceagain. The circuit will thus be returned to the state shown in thedrawing, with the ribbon feeding in the indicated direction.

The improved rewinding apparatus is applicable to a wide variety ofprinting machines, typewriters, and the like, as well as to otherapplications in which it is desired -to reel and re-reel an elongatedweb automatically from one roll to another. It will be apparent to thoseskilled in the art that various changes and modifications may be made inthe embodiment which has been described without departing from the truespirit and scope of the invention. For example, the control circuitmight comprise merely a single-pole double-throw toggle switch adaptedto reverse the clutch energization upon each subsequent actuation; andvarious other alternatives may be employed. Furthermore, the clutchcontrol means may be operated upon engagement of the paddle W1th afully-wound ribbon roll having a certain minimum diameter, as well as byengagement with a depleted roll. I therefore intend to define theinvention in the appended claims without limitation to the details ofthe illustrated embodiment.

What I claim is:

1. Automatic rewinding apparatus for an elongated web, comprising a pairof rolls rotatably supported on parallel axes for attachment to theopposite ends of an elongated web to reversibly wind the web thereon; apair of disengageable clutches each including an input drive element andan output drive element; each of said rolls being connected with theoutput drive element of a different one of said clutches; reversiblepressure-actuated control means operatively connected with said clutchesfor alternatively engaging either one thereof; motive means connected todrive the input elements of said clutches in opposite rotational senses;a pair of cams drivingly connected With said input elements; anoscillatory rock shaft provided with a sensing paddle, a crank arm, andan actuating element for said pressure-actuated means; a pair ofpivotally-mounted levers, and means biasing said levers in oppositeangular directions each toward engagement with one of said cams; saidcams being formed to release said levers alternately for actuation bysaid biasing means into driving engagement with said crank arm, tooscillate said paddle alternately into biased engagement with the Webrolled on each of said rolls, whereby the angular displac ments of saidactuating element are limited by the alternate engagements of saidpaddle with the Web rolls; said actuating element being arranged forangular displacement to a terminal position, to actuate said controlmeans and thus reverse the direction of winding of said web on saidrolls, as the web is fully wound on one roll and depleted from theother.

2. Automatic rewinding apparatus as recited in claim 1, in which saidlevers are mounted for pivotal movement about a common axis, saidbiasing means comprising a tension spring interconnecting said levers.

3. Automatic rewinding apparatus as recited in claim 2, in which saidlevers are provided with arms for alternate engagement with said crankto produce angular displacement of said shaft in opposite angulardirections from an intermediate neutral position, together with meansurging said crank toward the neutral position for returning said paddlefrom engagement with said rolls upon release. of said crank by saidlevers.

4. Automatic rewinding apparatus for an elongated web, comprising a pairof rolls rotatably supported on 'parallel axes for attachment to theopposite ends of an elongated web to reversibly wind the web thereon; apair of disengageable electromagnetic clutches each including anenergizing coil, an input drive element, and an output drive element;each of said rolls being connected with the output drive element of oneof said clutches; control means including pressure-actuated switch meansand circuit means electrically connected with said coils for alternativeenergization of either one thereof; motive means connected to drive theinput elements of said clutches in opposite rotational senses; a

pair of cams drivingly connected with said input elements; anoscillatory rock shaft provided with a sensing paddle, a crank arm, andan actuating element for said switch means; a pair of pivotally-mountedlevers, and means biasing said levers in opposite angular directionseach toward engagement with one of said cams; said cams being formed torelease said levers alternately for actuation by said biasing means intodriving engagement with said crank arm, to oscillate said paddlealternately into biased engagement with the web rolled on each of saidrolls, whereby the angular displacements of said actuating element arelimited by the alternate engagements of said paddle with the web rolls;said actuating element being arranged for angular displacement to aterminal position, to actuate said switch means and thus reverse thedirection of Winding of said web on said rolls, as the web is fullywound on one roll and depleted from the other.

5. Automatic rewindiug apparatus as recited in claim 4, in which saidswitch means comprise a normally-closed momentary-contact switch andnormally-open momentary-contact switch each arranged for actuation bysaid element upon angular displacement of said paddle to a differentterminal position engaging one of said rolls upon depletion of said webtherefrom; said circuit means including a relay having afirstdouble-throw contact connected to energize one of said clutch coilsupon energization of said relay, and to energize the other of saidclutch coils upon de-energization of said relay, said normally-openswitch being connected to energize said relay momentarily when actuated;said relay further having a holding contact connected to maintainenergization of said relay through said normally-closed switch followingmomentary energization by said normallyopen switch; said normally-closedswitch being adapted to de-energize said relay upon a subsequentactuation thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,114,494 10/1914Little. 2,584,734 2/ 1952 Owens 24257 2,634,063 4/1953 Paris et al.24267.4

MERVIN STEIN, Primary Examiner.

W. S. BURDEN, Assistant Examiner.

1. AUTOMATIC REWINDING APPARATUS FOR AN ELONGATED WEB, COMPRISING A PAIROF ROLLS ROTATABLY SUPPORTED ON PARALLEL AXES FOR ATTACHMENT TO THEOPPOSITE ENDS OF AN ELONGATED WEB TO REVERSIBLY WIND THE WEB THEREON; APAIR OF DISENGAGABLE CLUTCHES EACH INCLUDING AN INPUT DRIVE ELEMENT ANDAN OUTPUT DRIVE ELEMENT; EACH OF SAID ROLLS BEING CONNECTED WITH THEOUTPUT DRIVE ELEMENT OF A DIFFERENT ONE OF SAID CLUTCHES; REVERSIBLEPRESSURE-ACTUATED CONTROL MEANS OPERATIVELY CONNECTED WITH SAID CLUTCHESFOR ALTERNATIVELY ENGAGING EITHER ONE THEREOF; MOTIVE MEANS CONNECTED TODRIVE THE INPUT ELEMENTS OF SAID CLUTCHES IN OPPOSITE ROTATIONAL SENSES;A PAIR OF CAMS DRIVINGLY CONNECTED WITH SAID INPUT ELEMENTS; ANOSCILLATORY ROCK SHAFT PROVIDED WITH A SENSING PADDLE, A CRANK ARM, ANDAN ACTUATING ELEMENT FOR SAID PRESSURE-ACTUATED MEANS; A PAIR OFPIVOTALLY-MOUNTED LEVERS, AND MEANS BIASING SAID LEVERS IN OPPOSITEANGULAR DIRECTIONS EACH TOWARD ENGAGEMENT WITH ONE OF SAID CAMS; SAIDCAMS BEING FORMED TO RELEASE SAID LEVERS ALTERNATELY FOR ACTUATION BYSAID BIASING MEANS INTO DRIVING ENGAGEMENT WITH SAID CRANK ARM, TOOSCILLATE SAID PADDLE ALTERNATELY INTO BIASED ENGAGEMENT WITH THE WEBROLLED ON EACH OF SAID ROLLS, WHEREBY THE ANGULAR DISPLACEMENTS OF SAIDACTUATING ELEMENT ARE LIMITED BY THE ALTERNATE ENGAGEMENTS OF SAIDPADDLE WITH THE WEB ROLLS; SAID ACTUATING ELEMENT BEING ARRANGED FORANGULAR DISPLACEMENT TO A TERMINAL POSITION, TO ACTUATE SAID CONTROLMEANS AND THUS REVERSE THE DIRECTION OF WINDING OF SAID WEB ON SAIDROLLS, AS THE WEB IS FULLY WOUND ON ONE ROLL AND DEPLETED FROM THEOTHER.